High salinity environment rust layer with steel with excellent weather resistance

摘要

PROBLEM TO BE SOLVED: To provide a steel material with an unpainted rust layer excellent in corrosion resistance even in a severe corrosive environment where a large amount of air-borne salt is present, particularly in a seaside region or the like.;SOLUTION: A steel material with a rust layer has the rust layer formed on the surface of a base steel material. The rust layer contains Nb and Sn and the number of Nb atoms in the rust layer is 0.01 or more, as the maximum value, relative to 100 Fe atoms, while the number of Sn atoms in the rust layer is 0.005 or more, as the maximum value, relative to 100 Fe atoms.;COPYRIGHT: (C)2013,JPO&INPIT